Preparations

Display a clear jar filled with pennies in the classroom a few days before the lesson starts. Let the students make observations about the pennies in the jar but not take the pennies out of the jar.

Divide students in to groups with 3 to 5 members.

Have each group come up with a group guesstimate for the number of pennies in the jar. Each group can have a chance to examine the jar before making their guesstimate.

Have each group write their guesstimate on a sticky note and place it on a classroom chart.

Remove about half of the pennies from the jar. Have the class decide how to determine about half.

Count out the half of the pennies that were removed.

Allow each group to make an estimate based on this new information. Have each group put their estimate on a different colored sticky note and add it to the classroom chart. Keep the group’s guesstimate and estimate next to each other.

Have the students in their groups answer the following questions. The students can write their group answers in their math journal.

What is the order of the guesstimates from lowest to highest?

What is the order of the estimates from lowest to highest?

What is the range for the guesstimates?

What is the range for the estimates?

Find the differences between the guesstimates and estimates for each group.

Have students present their answers to the class.

Pick a group to count the total amount of pennies in the jar and add the actual number to the chart.

Discuss as a class different strategies for making better estimates.

Enrichments/Extensions

Students can make simple word problems using the data on the classroom chart and the information they found in their groups.

Students can do research to find out what they could purchase with the exact amount of pennies in the jar.

Assess the groups' learning based on the information in their math journals and on the group presentation they gave when they answered the above questions. Give grades to the groups.

K.CC.2. Count forward beginning from a given number within the known sequence (instead of having to begin at 1).

K.CC.3. Write numbers from 0 to 20. Represent a number of objects with a written numeral 0-20 (with 0 representing a count of no objects).

Discipline: MathDomain: K.CC Counting and CardinalityGrade(s):
Grade K
Cluster: Count to tell the number of objectsStandards:

K.CC.4. Understand the relationship between numbers and quantities; connect counting to cardinality.

When counting objects, say the number names in the standard order, pairing each object with one and only one number name and each number name with one and only one object.

Understand that the last number name said tells the number of objects counted. The number of objects is the same regardless of their arrangement or the order in which they were counted.

Understand that each successive number name refers to a quantity that is one larger.

K.CC.5. Count to answer "how many?" questions about as many as 20 things arranged in a line, a rectangular array, or a circle, or as many as 10 things in a scattered configuration; given a number from 1-20, count out that many objects.